What do you know about the catheter walk? Can you spot the difference?

#1

#2

The difference in electrode deflection from #1 to #2 can be minimal but one will result in successful creation, the other in failed creation. I'll use my crude, homemade model to try to explain:

In example #1, the arterial and venous electrodes are well aligned

With proper alignment, the arterial ceramic footplate will significantly deflect the venous electrode when walked

In example #2, the electrodes are askew

Although you may see some deflection with catheter walking, it will not be nearly as obvious and/or convincing. If you fire in an askew position, the venous electrode will miss the ceramic footplate and you won't get AVF creation

What happens if you don't recognize the catheter misalignment?!

As we saw on the model, the electrodes won't connect and fistula creation will be unsuccessful. Can you spot the difference? (Don't worry if your answer is )

#1 - Electrodes misaligned and do NOT coapt

#2 - Proper alignment, fistula creation successful

Again, don't worry if you couldn't be sure of the difference. If you're aligned, you know and everyone's all like



And if you're not aligned, the mood is more



Buuut, you're going to confirm creation with contrast injection anyway so that will tell you for sure

Last additions to this thread (can you figure out when I have academic time )

How does misalignment happen?

The first possibility is you inserted the electrodes wrong.

Me: "This is what your rotational indicators are for!"

You: "What the heck are rotational indicators?!"

They are little cutout squares on the electrodes that look thin edged when well positioned and a solid dark square when in the wrong position. The newer generation device has loads of rotational indicators to help you out

The second option, and more subtle technical issue is that you haven't obtained the true "widest view." If your image intensifier is not angled properly to place the vessels in the "widest view," your catheters will not align properly.

Example 1: NOT in widest view (vessels will be a bit overlapped in the 2D fluoro image)

Example 2: CORRECTLY in widest view (see how the artery and veins are now all in plane?)

After trial and error (and lots of squinting), I've found the easiest way to get the proper image intensifier angle is to use US first to get the vessels in plane and THEN line the image intensifier up with the US angle.